The ratio of 5-hydroxytryptophol to 5-hydroxyindole-3- acetic acid (5HTOIJSHIAA) in urine was compared with concentrations of ethanol and methanol as a way to monitor recent alcohol consumption. During detoxification of alco-... more
The ratio of 5-hydroxytryptophol to 5-hydroxyindole-3- acetic acid (5HTOIJSHIAA) in urine was compared with concentrations of ethanol and methanol as a way to monitor recent alcohol consumption. During detoxification of alco- hol-dependent subjects, ethanol persisted longer in urine than in breath or plasma. Blood and urinary methanol remained increased for 2-6 h after blood ethanol had returned to background concentrations,
Research Interests:
Research Interests:
Research Interests:
It has been discovered recently that exogenous substances are detectable in exhaled breath after intake. Exhaled breath therefore constitutes a new possible matrix in clinical pharmacology and toxicology. The present work was aimed at... more
It has been discovered recently that exogenous substances are detectable in exhaled breath after intake. Exhaled breath therefore constitutes a new possible matrix in clinical pharmacology and toxicology. The present work was aimed at exploring this possibility further by a study on patients treated for attention-deficit/hyperactivity disorder with D-amphetamine and methylphenidate. Thirteen patients (age range: 32-61 years; 5 women) were included in the study, and breath and urine samples were collected at different times in the dose interval. Analyses of breath and urine samples were done with liquid chromatography-mass spectrometry methods. Urine was examined for amphetamine, methylphenidate, and its metabolite ritalinic acid. Among the 9 patients who received D-amphetamine medication in daily doses of 20-100 mg, amphetamine was detected in all subjects in amounts ranging from 1200 to 30,800 picogram per filter. Among 8 patients receiving methylphenidate medication in daily doses...
Research Interests:
Four routine assays commonly used for monitoring plasma methotrexate (MTX) during high-dose therapy were validated by HPLC as the comparison method. MTX and its main metabolite, 7-hydroxymethotrexate (7-OHMTX), were analyzed by HPLC with... more
Four routine assays commonly used for monitoring plasma methotrexate (MTX) during high-dose therapy were validated by HPLC as the comparison method. MTX and its main metabolite, 7-hydroxymethotrexate (7-OHMTX), were analyzed by HPLC with postcolumn derivatization and fluorometric detection. About 200 clinical plasma samples from 13 children with acute lymphoblastic leukemia who received 5-8 g/m2 MTX as 24-h infusions were analyzed. The fraction of measured concentrations of MTX that were within 75-125% of the values obtained by HPLC were 64.5% for enzyme inhibition assay, 56.4% for fluorescence polarization immunoassay with polyclonal antibodies (FPIA1; Abbott), 58.9% for FPIA2 (with monoclonal antibodies; Abbott), and 46.4% for enzyme-multiplied immunoassay (Emit; Syva). All nonchromatographic procedures were subject to interferences from MTX plasma metabolites or endogenous substances. The interference from 7-OHMTX was, however, somewhat less pronounced for FPIA2 (monoclonal) than...
Research Interests:
We have developed an assay for the simultaneous determination of methotrexate (MTX) and its main metabolites, 7-hydroxymethotrexate (7-OHMTX) and 2,4-diamino-N10-methylpteroic acid (DAMPA) in plasma, urine and saliva meeting the... more
We have developed an assay for the simultaneous determination of methotrexate (MTX) and its main metabolites, 7-hydroxymethotrexate (7-OHMTX) and 2,4-diamino-N10-methylpteroic acid (DAMPA) in plasma, urine and saliva meeting the requirement of rapidity for routine use in high-dose MTX therapy and the requirement of sensitivity for its potential use in therapeutic drug monitoring in low-dose MTX therapy. Sample preparation is based on solid-phase extraction using C8 Isolute cartridges. Chromatographic separation was achieved with a reversed-phase column (C18), and quantitation by subsequent exposure to UV light of 254 nm, which converted MTX and its two metabolites by photolytic oxidation to fluorescent products. The recoveries of MTX, 7-OHMTX and DAMPA from plasma at 100 nmol/l were 85.8, 91.1 and 102.3%, respectively. The limits of detection for MTX, 7-OHMTX and DAMPA in plasma and saliva were 0.1 nmol/l. In urine the limit of detection was 10 nmol/l for all compounds. The limits o...
Research Interests:
Products for on-site urine drug testing offer the possibility to perform screening for drugs of abuse directly at the point-of-care. This is a well-established routine in emergency and dependency clinics but further evaluation of... more
Products for on-site urine drug testing offer the possibility to perform screening for drugs of abuse directly at the point-of-care. This is a well-established routine in emergency and dependency clinics but further evaluation of performance is needed due to inherent limitations with the available products. Urine drug testing by an on-site product was compared with routine laboratory methods. First, on-site testing was performed at the laboratory in addition to the routine method. Second, the on-site testing was performed at a dependency clinic and urine samples were subsequently sent to the laboratory for additional analytical investigation. The on-site testing products did not perform with assigned cut-off levels. The subjective reading between the presence of a spot (i.e. negative test result) being present or no spot (positive result) was difficult in 3.2% of the cases, and occurred for all parameters. The tests performed more accurately in drug negative samples (specificity 96%) but less accurately for detecting positives (sensitivity 79%). Of all incorrect results by the on-site test the proportion of false negatives was 42%. The overall agreement between on-site and laboratory testing was 95% in the laboratory study and 98% in the clinical study. Although a high degree of agreement was observed between on-site and routine laboratory urine drug testing, the performance of on-site testing was not acceptable due to significant number of false negative results. The limited sensitivity of on-site testing compared to laboratory testing reduces the applicability of these tests.
Research Interests:
The central nervous system-active medication acamprosate has been shown to modulate alcohol-related behavior in both preclinical and clinical studies. Although commonly used in the treatment of alcohol dependence, there are still... more
The central nervous system-active medication acamprosate has been shown to modulate alcohol-related behavior in both preclinical and clinical studies. Although commonly used in the treatment of alcohol dependence, there are still unanswered questions concerning the pharmacokinetic properties of acamprosate. The aims of the present study were to 1) to validate liquid chromatography-mass spectrometry as a method to study the presence of acamprosate in plasma and cerebrospinal fluid (CSF) in humans; and 2) validate previous results on clinically important pharmacokinetic data for acamprosate. In an open label, single-site design, 13 healthy males and females were recruited to 22 days of oral acamprosate treatment (1998 mg/day). Subjects provided in all 256 plasma samples for analysis at regular intervals at Day 1, 7, 14, and 22 of treatment. On Day 22, subjects also left a sample of CSF for measurement of acamprosate. The results showed that steady-state level of acamprosate was accomplished within 5 days after the start of treatment and remained fairly stable for 2 to 3 days after termination of treatment. Variations in plasma concentrations corresponded to earlier studies and did not exceed those for comparable pharmacotherapeutic agents. Acamprosate concentrations in the CSF were below the limit of quantification, ie, estimated concentrations between 9 and 33 ng/mL. Plasma concentrations were more than 25 times higher than in lumbar CSF. The low CSF levels seen after 3 weeks of treatment may provide an explanation to the delay in therapeutic effect noticed in treatment studies on acamprosate. A longer duration of treatment might be necessary to obtain clinically significant brain levels of acamprosate. In summary, the present study validated liquid chromatography-mass spectrometry as a method for assessment of compliance to acamprosate treatment. Furthermore, the results suggest that the mechanism of action of acamprosate needs to be further explored with regard to the peripheral actions of the drug.
Research Interests: Analytical Chemistry, Mass Spectrometry, Adolescent, Therapeutic drug monitoring, Cerebrospinal Fluid, and 14 moreHumans, Calibration, Female, Male, Young Adult, High Pressure Liquid Chromatography, Shell Half-Life, Aged, Middle Aged, Adult, Reproducibility of Results, Taurine, Mass Spectroscopy, and Area Under Curve
A new high-performance liquid chromatographic method for the quantitative determination of methotrexate (MTX) and its metabolite 7-hydroxymethotrexate (7-OHMTX) in blood plasma and urine was developed. The method utilized a solid-phase... more
A new high-performance liquid chromatographic method for the quantitative determination of methotrexate (MTX) and its metabolite 7-hydroxymethotrexate (7-OHMTX) in blood plasma and urine was developed. The method utilized a solid-phase extraction procedure (Certify II cartridges) for the simultaneous isolation of MTX and 7-OHMTX. Chromatographic separation was achieved using a C18 reversed-phase column with isocratic elution. The eluent was irradiated with UV light of 254 nm, which converted MTX and 7-OHMTX by photolytic oxidation to fluorescent products. The limits of detection of MTX and 7-OHMTX in plasma were approximately 0.2 and 1 nmol/L, respectively. The intraday variability in the quantitation of MTX and 7-OHMTX was less than 8% down to 1 nmol/L and 4.6 nmol/L, respectively. Both MTX and 7-OHMTX could be detected in plasma from a patient being treated for rheumatoid arthritis 1 week after the last dose (10 mg orally).
Research Interests:
A limited sampling strategy for determination of the area under the plasma concentration versus time curve (AUC) of methotrexate (MTX) in patients with rheumatoid arthritis (RA), treated with weekly oral doses, has been validated.... more
A limited sampling strategy for determination of the area under the plasma concentration versus time curve (AUC) of methotrexate (MTX) in patients with rheumatoid arthritis (RA), treated with weekly oral doses, has been validated. Stepwise linear regression analysis was used for optimal inclusion of data points in mathematical models to estimate AUC. A new plot for evaluation of the accuracy and precision of the estimated AUC values was introduced in the present study. By plotting the ratio of determined/estimated AUC values versus estimated AUC values, the influence of number of sampling points on the precision and accuracy of estimated AUC values was easily validated. Our results show that AUC values of MTX in RA patients can be estimated from a single plasma sample at 3 h or preferably, due to increased precision, by additional samplings at 5 and 1 h. A further increase of the number of sampling points increased the precision of the AUC estimates only to a minor extent. The accuracy of the estimated AUC values was independent of the number of sampling points. A limited sampling procedure can now be used for further studies on the relationship between MTX levels and its effects.
Research Interests:
Ethyl glucuronide is a minor metabolite of ethanol, and its presence in urine can be used as a laboratory test to detect recent alcohol intake, even for some time after the ethanol is no longer measurable. A simple analytical procedure... more
Ethyl glucuronide is a minor metabolite of ethanol, and its presence in urine can be used as a laboratory test to detect recent alcohol intake, even for some time after the ethanol is no longer measurable. A simple analytical procedure was developed based on direct injection of urine diluted with a deuterated internal standard into an electrospray liquid chromatographic-mass spectrometric (LC-MS) system. A novel LC system using a porous graphite column (Hypercarb) enabled an isocratic elution with retention times of 5-6 minutes. The intra- and inter-assay coefficients of variation were 2-12%, and the measuring range was 0.1-1,500 mg/L (0.45-6,750 micromol/L). Ethyl glucuronide was found to be stable in urine for more than 4 days at room temperature, and no artifactual formation was observed on storage of urine samples fortified with 1% ethanol. Ethyl glucuronide was not detected in urine samples collected after abstinence from alcohol. Intake of a very low amount (7 g) of ethanol produced ethyl glucuronide values up to 8.4 mg/L after 4 hours and was still detectable at 6 hours. When the method was applied for routine screening of 252 clinical urine samples (range, 0-1,240 mg/L), it fulfilled the need for a simple and reliable assay to be used in the evaluation of urinary ethyl glucuronide as a routine test of recent alcohol intake.
Research Interests:
Research Interests: Psychopharmacology, Cortisol, Humans, Cues, Alcoholism, and 16 moreGalvanic Skin Response, Female, Alcohol Drinking, Male, Ethanol, Patient Compliance, Body Temperature, Middle Aged, Alcohol dependence, Adult, Analysis of Variance, Time Factors, Randomized Controlled Trial, Taurine, Mechanism of action, and Pain Measurement
A new high-performance liquid chromatographic assay was used to determine methotrexate (MTX) and its main metabolite, 7-hydroxymethotrexate (7-OH-MTX), in the plasma (n = 17) and urine (n = 14) of children (age 3-12 years) on maintenance... more
A new high-performance liquid chromatographic assay was used to determine methotrexate (MTX) and its main metabolite, 7-hydroxymethotrexate (7-OH-MTX), in the plasma (n = 17) and urine (n = 14) of children (age 3-12 years) on maintenance therapy for acute lymphocytic leukemia (n = 14) or non-Hodgkin's lymphoma (n = 3). Each child received oral doses of weekly MTX (4.0-29 mg/m2) and daily 6-mercaptopurine (40-111 mg/m2). Plasma samples were collected daily from two children during the 1-week dose interval. A limited sampling strategy was designed, whereby 2 days of blood sampling were used in the other 15 patients. Morning urine samples were collected daily for 1 week following MTX intake from 14 of the children. MTX was detectable in all plasma and urine samples for the entire dose interval. The main metabolite, 7-OH-MTX, could be detected in plasma and urine from all patients on the first day after dose intake but only in a few patients during the whole dose interval. Interpatient variability of MTX and 7-OH-MTX levels was high at all points during the week. Significant correlation were found between the urinary MTX levels on days 2 and 7 and plasma MTX levels on day 2 after intake. No significant correlation was found between drug levels in plasma or urine and liver function tests in the children showing signs of mild liver injury. This assay provides a tool for further studies on the role of pharmacokinetics for the clinical effects of weekly oral low-dose MTX given alone or in combination with 6-mercaptopurine.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
The urinary excretion patterns of the serotonin (5-hydroxytryptamine; 5-HT) metabolites 5-hydroxyindole-3-acetic acid (5-HIAA) and 5-hydroxytryptophol (5-HTOL) were examined after ingestion of bananas, a food rich in 5-HT. The bananas... more
The urinary excretion patterns of the serotonin (5-hydroxytryptamine; 5-HT) metabolites 5-hydroxyindole-3-acetic acid (5-HIAA) and 5-hydroxytryptophol (5-HTOL) were examined after ingestion of bananas, a food rich in 5-HT. The bananas contained on an average 25 micrograms 5-HT/g pulp. Both urinary 5-HIAA and 5-HTOL increased markedly (15- to 30-fold) shortly after eating 3-4 bananas, with the highest concentrations found in urine specimens collected after 2-4 h, and did not return to normal until after 8-10 h. The excretion of 5-HIAA increased from a control mean value of 3.9 mg/24 h to 12.7 mg/24 h, when conventional diets were supplemented with 3-4 bananas. The corresponding results for 5-HTOL were 16.8 micrograms/24 h and 60.7 micrograms/24 h, respectively. Of the banana-derived 5-HT ingested, 60-80% was recovered in the urine as 5-HIAA and only 0.3-0.5% as 5-HTOL. However, since both the time-course and relative increase in 5-HTOL was similar to that of 5-HIAA, there was no effect on the urinary 5-HTOL to 5-HIAA ratio. By contrast, acute alcohol consumption produced a considerable elevation of this ratio.
Research Interests:
The effect of acute ethanol consumption on serotonin metabolism was examined in healthy volunteers in the fasted and fed state by determination of plasma and urinary levels of the serotonin metabolites 5-hydroxyindole-3-acetic acid... more
The effect of acute ethanol consumption on serotonin metabolism was examined in healthy volunteers in the fasted and fed state by determination of plasma and urinary levels of the serotonin metabolites 5-hydroxyindole-3-acetic acid (5-HIAA) and 5-hydroxytryptophol (5-HTOL). The plasma and urinary levels of 5-HIAA were reduced by about 40% and 25%, while the 5-HTOL levels were increased on an average 7-fold and 50-fold, respectively, after oral intake of ethanol (0.8 g/kg) over 30 min in a fasted state. The maximal effect on both 5-HIAA and 5-HTOL levels was found 4-6 h after starting drinking. Urinary 5-HTOL and the 5-HTOL/5-HIAA ratio did not return to baseline until 19 h after the start of the administration (i.e., about 10 h after ethanol reached zero level). The mean 24-h excretion of 5-HTOL was increased 15-fold by the ethanol intake, while the 5-HIAA excretion was not significantly different. A clear dose dependent effect was observed in one individual who also ingested a lower amount of ethanol (0.5 g/kg). When ethanol (0.8 g/kg) was ingested over 3 h together with food, the urinary level of 5-HTOL and the 5-HTOL/5-HIAA ratio did not return to baseline until after 20-22 h. In other subjects who had unlimited access to ethanol and ingested between 1.3-2.3 g/kg together with food, the time to reach baseline 5-HTOL/5-HIAA ratio in urine ranged from 20 h to over 26 h.
Research Interests:
The distribution of free and conjugated forms of the serotonin (5-hydroxytryptamine) metabolite 5-hydroxytryptophol (5HTOL) in human urine was determined. 5HTOL was analyzed using a sensitive and specific gas chromatographic-mass... more
The distribution of free and conjugated forms of the serotonin (5-hydroxytryptamine) metabolite 5-hydroxytryptophol (5HTOL) in human urine was determined. 5HTOL was analyzed using a sensitive and specific gas chromatographic-mass spectrometric method. The sulfate and glucuronide conjugated forms were measured indirectly following enzymatic hydrolysis. Total 5HTOL levels in control samples ranged between 98-301 nM, in samples collected following ingestion of bananas, a food rich in serotonin, between 450-3292 nM, following alcohol consumption between 863-13326 nM, and in samples obtained from patients with serotonin producing carcinoid tumors between 1695-3793 nM. Free 5HTOL accounted for less than 4% of total 5HTOL in all samples. Sulfate conjugated 5HTOL was calculated to comprise about 17% of total 5HTOL in the control samples and 15% in the alcohol samples, whereas the mean proportion was significantly increased to 33% and 27% in the samples collected after ingestion of bananas and from patients with carcinoid tumors, respectively. The results show that conjugation with glucuronic acid followed by urinary excretion is normally the predominant route for elimination of 5HTOL in man. However, in situations of elevated levels of total 5-hydroxyindoles originating from dietary sources or serotonin producing tumors in the gut, sulfate conjugation becomes more important.
Research Interests:
A high-performance liquid chromatographic method for the routine determination of elevated urinary levels of the serotonin metabolite 5-hydroxytryptophol (5-HTOL) is described. Urine samples were treated with beta-glucuronidase, and... more
A high-performance liquid chromatographic method for the routine determination of elevated urinary levels of the serotonin metabolite 5-hydroxytryptophol (5-HTOL) is described. Urine samples were treated with beta-glucuronidase, and 5-HTOL was isolated by solid-phase extraction on a small Sephadex G-10 column prior to injection onto an isocratically eluted C18 reversed-phase column. Detection of 5-HTOL was performed electrochemically at +0.60 V vs. Ag/AgCl. The limit of detection was ca. 0.05 microM, and the intra-assay coefficients of variation were below 6% with urine samples containing 0.2 and 2.1 microM 5-HTOL and a standard solution of 2.0 microM (n = 5). The recovery of 5-HTOL after the sample clean-up procedure was close to 100%. A good correlation (r2 = 0.97; n = 12) was obtained between the present method and a sensitive and specific gas chromatographic-mass spectrometric method. The total (free plus conjugated) 5-HTOL levels in urine were normally below 0.2 microM, but after an acute dose of alcohol they increased to 0.5-15 microM.
Research Interests: Analytical Chemistry, Chromatography, Electrochemistry, Serotonin, Humans, and 8 moreSolid Phase Extraction, Alcohol Drinking, Coefficient of Variation, High Pressure Liquid Chromatography, Liquid Chromatography / Electrospray Ionization Mass Spectrometry, Liquid Chromatography, Biological markers, and Biochemistry and cell biology
A method based on direct injection of diluted urine for the identification and quantification of amphetamine, methamphetamine, 3,4-methylenedioxymetamphetamine and 3,4-methylenedioxyamphetamine in human urine by electrospray ionisation... more
A method based on direct injection of diluted urine for the identification and quantification of amphetamine, methamphetamine, 3,4-methylenedioxymetamphetamine and 3,4-methylenedioxyamphetamine in human urine by electrospray ionisation liquid chromatography-tandem mass spectrometry was validated for use as a confirmation procedure in urine drug testing. Two deuterium labelled analogues, amphetamine-D5 and 3,4-methylenedioxymetamphetamine-D5, were used as internal standards. Twenty microliter aliquots of urine were mixed with 80 microL internal standard solution in autosampler vials and 10 microL was injected. The chromatographic system consisted of a 2.0 mmx100 mm C18 column and the gradient elution buffers used acetonitrile and 25 mmol/L formic acid. Two product ions produced from the protonated molecules were monitored in the selected reaction monitoring mode. The intra- and inter-assay variability (coefficient of variation) was between 5 and 16% for all analytes at 200 and 6000 ng/mL levels. Ion suppression occurred early after injection but did not affect the identification and quantification of the analytes in authentic urine samples. The method was further validated by comparison with a reference gas chromatographic-mass spectrometric method using 479 authentic urine samples. The two methods agreed almost completely (99.8%) regarding identified analytes when applying a 150 ng/mL reporting limit. Four deviating results were observed for 3,4-methylenedioxymethamphetamine and this was due to uncertainty in quantification around the reporting limit. For the quantitative results the slope of the regression lines were between 0.9769 and 1.0146, with correlation coefficients>0.9339. We conclude that the presented liquid chromatographic-tandem mass spectrometric method is robust and reliable, and suitable for use as a confirmation method in urine drug testing for amphetamines.
Research Interests: Analytical Chemistry, Humans, Methamphetamine, Amphetamine, Tandem Mass Spectrometry, and 10 moreCoefficient of Variation, High Performance Liquid Chromatography, Formic Acid, Liquid Chromatography, Gas Chromatography/mass Spectrometry, Reproducibility of Results, Correlation coefficient, Direct Injection, SELECTED REACTION MONITORING, and Biochemistry and cell biology
A direct liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method for measurement of urinary Delta(9)-tetrahydrocannabinol carboxylic acid (THCA) was developed. The method involved dilution of the urine sample with water... more
A direct liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method for measurement of urinary Delta(9)-tetrahydrocannabinol carboxylic acid (THCA) was developed. The method involved dilution of the urine sample with water containing (2)H(9)-deuterated analogue as internal standard, hydrolysis with ammonia, reversed phase chromatography using a Waters ultra-performance liquid chromatography (UPLC) equipment with gradient elution, negative electrospray ionization, and monitoring of two product ions in selected reaction monitoring mode. The measuring range was 2-1000 ng/mL for THCA, and the intra- and inter-assay imprecision, expressed as the coefficient of variation, was below 5%. Influence from urine matrix on ionization efficiency was noted in infusion experiments, but was compensated for by the internal standard. Comparison with established gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry methods in authentic patient samples demonstrated accuracy in both qualitative and quantitative results. A small difference in mean ratios (~15%) may be explained by the use of different hydrolysis procedures between methods. In conclusion, the high efficiency LC-MS/MS method was capable of accurately identify and quantify THCA in urine with a capacity of 14 samples per hour.
Research Interests:
Research Interests:
Testing for drugs of abuse in sample matrices alternative to urine such as blood, sweat, and saliva have received increasing attention and is needed, for example, in traffic medicine. Human breath is known to contain a large number of... more
Testing for drugs of abuse in sample matrices alternative to urine such as blood, sweat, and saliva have received increasing attention and is needed, for example, in traffic medicine. Human breath is known to contain a large number of substances including non-volatile molecules. We explore whether intake of amphetamines could be detected by analytical investigation of exhaled breath from drug addicts. Exhaled breath was collected from 12 drug addict patients after recovering from acute intoxication. Self-reported intake of "amphetamine" was confirmed by analysis of urine and plasma. The compounds were trapped by filtering the air through a modified silica surface and subsequently analyzed by a combined liquid chromatography-tandem mass spectrometry method. As a control, exhaled breath was collected in the same way from eight healthy volunteers. Here we report for the first time that amphetamine and methamphetamine are present in exhaled breath following ingestion of these compounds by drug addicts. Both amphetamine and methamphetamine were indisputably identified by means of the mass spectrometry technique in exhaled breath samples from all 12 patients. Identifications were based on monitoring two product ions in selected reaction monitoring mode and having correct relative ratios (+/- 20%). Excretion rates ranged from 0.2 to 139 pg/min. No amphetamine or methamphetamine was detected in the control subjects. This finding, using a yet non-validated sampling procedure, opens a new possibility for drugs-of-abuse testing. Collection of exhaled breath is likely to be more convenient and safe as compared to matrices presently in use.
Research Interests:
Research Interests: Medical Microbiology, Clostridium difficile, Fungi, Chemical and Biological Engineering, Humans, and 20 moreFemale, Anaerobic Bacteria, Male, Bacteria, Plasma, Candida albicans, Cephalosporins, Human Experimentation, Spectrum, Gram-negative bacteria, Anti-Bacterial Agents, Adult, Ecological Impact, Feces, Antimicrobial agents, Gastrointestinal Tract, Intestinal Microflora, Healthy Subjects, Minimum inhibitory concentration, and Metagenome
The "STRIDA" project monitors the occurrence and trends of new psychoactive substances (NPS; "Internet drugs/designer drugs/legal highs")... more
The "STRIDA" project monitors the occurrence and trends of new psychoactive substances (NPS; "Internet drugs/designer drugs/legal highs") in Sweden, and collects information about their clinical symptoms, toxicity and associated health hazards. The initial results of the project documented a widespread use of many different NPS by mainly adolescents and young (age range 13-63 years, median 20), male (79%) adults, among cases of drug intoxications presenting at emergency departments and intensive care units across the country. The new substances were identified in samples of urine and blood by a multi-component LC-MS/MS method, and the severity of clinical symptoms were graded by the Poisoning Severity Score (PSS). Of the initial 189 samples submitted for laboratory investigation, 156 (83%) tested positive for at least one drug. Besides classical substances such as ethanol, cannabis and amphetamines, many NPS were detected comprising synthetic cannabinoid receptor agonists ("Spice"), piperazines, substituted phenethylamines, synthetic cathinones, hallucinogenic tryptamines, piperidines, opioid related substances, ketamine and related substances, and GABA analogues (in total more than 50 substances). About half of the cases were demonstrated to be multiple drug intoxications, sometimes making it hard to associate the clinical presentations with one specific substance. In conclusion, the STRIDA project has documented use of a broad variety of NPS among mainly young people all over Sweden.
Research Interests:
Research Interests:
Children with juvenile rheumatoid arthritis (JRA) have been reported to require higher doses (per kg body weight) of methotrexate (MTX) than adults with rheumatoid arthritis to control their disease. The purpose of the present study was... more
Children with juvenile rheumatoid arthritis (JRA) have been reported to require higher doses (per kg body weight) of methotrexate (MTX) than adults with rheumatoid arthritis to control their disease. The purpose of the present study was to characterise the plasma pharmacokinetics of MTX and its major metabolite, 7-hydroxymethotrexate (7-OHMTX) in children, and to compare the results with those previously obtained in adults. Thirteen patients (age 5-16 y) with JRA (median disease duration 5.5 y) were studied after once weekly oral administration of MTX (median 0.21 mg.kg-1). The analytical method was sufficiently sensitive to permit determination of plasma and urinary concentrations of MTX and 7-OHMTX during the entire dose interval in most of the patients. The dose normalized area under the plasma concentration versus time-curve (AUC) of MTX increased with the age of the children and was lower than previously found in adults. The dose normalized AUC of 7-OHMTX was not dependent on age. No correlation was found between the AUCs of MTX and 7-OHMTX. The results suggest that the age-dependence of the pharmacokinetics of MTX might explain the observation that at least some children require higher doses of MTX than adults to obtain a sufficient therapeutic effect.
Research Interests:
To further characterize pregnancy-induced alterations in the pharmacokinetics of lamotrigine (LTG). Fifteen women treated with LTG were studied during 17 pregnancies. Complete trough blood samples from all trimesters and baseline... more
To further characterize pregnancy-induced alterations in the pharmacokinetics of lamotrigine (LTG). Fifteen women treated with LTG were studied during 17 pregnancies. Complete trough blood samples from all trimesters and baseline > 1 month after delivery were available for 12 pregnancies (Group A), whereas, five contributed with samples only from the third trimester and baseline (Group B). High-performance liquid chromatography (HPLC) was used to determine LTG plasma concentrations, and liquid chromatography-mass spectrometry to assay the main metabolite 2-N-lamotrigine glucuronide (2-N-GLUC) in plasma. In group A, the mean dose/plasma concentration ratio (D/C) of LTG at baseline after pregnancy was 66.5 +/- 17.9 (+/- SD) L/day and approximately 250% higher in late pregnancy. The mean lamotrigine-2-N-glucuronide/lamotrigine plasma concentration ratio (2-N-GLUC/LTG) was 0.349 +/- 0.141 (+/- SD) at baseline and 147% higher in late pregnancy. Taking group A and B together, the 2-N-GLUC/LTG ratio was 175% higher in the third trimester compared to baseline. Our study confirms a significant decline in LTG plasma levels during pregnancy in women on monotherapy with LTG. An increased 2-N-GLUC/LTG ratio suggests that this decline may be related to an increased metabolism of LTG by glucuronidation.
Research Interests:
The increasing number of new psychoactive substances made available for recreational drug use has created a challenge for clinical toxicology and drug testing laboratories. As a consequence, the routine immunoassay drug testing may become... more
The increasing number of new psychoactive substances made available for recreational drug use has created a challenge for clinical toxicology and drug testing laboratories. As a consequence, the routine immunoassay drug testing may become less effective due to an increased occurrence of false negative and false positive screening results. This work aimed to extend the knowledge about analytical cross-reactivity of new substances in selected CEDIA, EMIT, and KIMS immunoassays for drugs-of-abuse screening. Urine standards were prepared by spiking blank urine with 45 new substances. Authentic urine samples from intoxication cases identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) were also studied. Several new psychoactive substances were demonstrated to display cross-reactivity in the immunoassays. CEDIA Amphetamine/Ecstasy and EMIT d.a.u. Amphetamine Class tests showed the highest reactivity towards the new drugs, which was expected since many have amphetamine-like structure and activity. In the samples from authentic cases, five new substances displayed 100% detection rate in the CEDIA Amphetamine/Ecstasy test. In conclusion, cross-reactivity data in routine urine drug screening immunoassays for a number of new psychoactive substances not studied before were reported. In both spiked and authentic urine samples, some new substances showed significant cross-reactivity and are thus detectable in the routine screening methods.
Research Interests:
The efficacy of stimulant treatment in patients with substance use disorders and comorbid attention deficit hyperactivity disorder (ADHD) has been tested for cocaine and alcohol dependence but so far no studies have been conducted in... more
The efficacy of stimulant treatment in patients with substance use disorders and comorbid attention deficit hyperactivity disorder (ADHD) has been tested for cocaine and alcohol dependence but so far no studies have been conducted in amphetamine dependent individuals. The present trial was a pilot study aiming to test the feasibility of treating amphetamine dependent patients with comorbid ADHD with central stimulant medication. The study was a double-blind, placebo controlled trial with parallel groups design comparing the efficacy of a fixed dose (72mg) of OROS methylphenidate (MPH) with placebo (PL) in reducing ADHD symptoms in currently abstinent adults with amphetamine dependence and ADHD. Twenty-four treatment seeking patients who met the DSM IV criteria for amphetamine dependence and ADHD were randomized to MPH/PL. The trial was conducted at an outpatient facility with twice weekly visits, measuring ADHD symptoms and drug use. Patients rated their ADHD symptoms on a weekly basis and provided supervised urine specimens for drug toxicology twice weekly. All patients participated in weekly sessions of a skills training programme. Both the groups significantly reduced their self-rated ADHD symptoms during the 12-week treatment but there was no difference between the two treatment arms. Drug use, both measured by urine toxicology and self-report did not differ between the groups. No difference was found between the two groups with regards to craving for amphetamine or in retention in treatment. Larger studies with higher doses combined with individual dosage and longer follow-up periods are warranted.
Research Interests: Attention-Deficit/Hyperactivity Disorder, Clinical Trial, Drug Use, Humans, Substance Use, and 14 moreChronic Disease, Female, Male, Pilot study, Alcohol dependence, Adult, Sustained Drug Release, Randomized Controlled Trial, Patient Participation, Pilot Projects, Methylphenidate, Delayed-Action Preparations, Substance Use Disorder, and Drug Tolerance
Problems associated with the increasing abuse of plant-derived psychoactive substances have recently attracted attention. This study involved bioanalytical and clinical examinations of intoxication cases suspected to be linked to such... more
Problems associated with the increasing abuse of plant-derived psychoactive substances have recently attracted attention. This study involved bioanalytical and clinical examinations of intoxication cases suspected to be linked to such plant materials. Urine samples were collected at emergency wards in Sweden from patients who either admitted or were suspected of ingestion of psychoactive plant materials. The bioanalytical investigation employed a liquid chromatography-tandem mass spectrometry multicomponent method covering 10 plant-derived substances (atropine, dimethyltryptamine, ephedrine, harmaline, harmine, ibogaine, lysergic acid amide, psilocin, scopolamine, and yohimbine) and a gas chromatography-mass spectrometry method for asarone. Routine testing for illicit drugs was also performed. Over a 4-year period, 103 urine samples collected from mainly young people (age range 13-52 years, median 19) were studied. Among 53 cases where ingestion of any of the 11 plant-derived substances covered in this study was admitted or suspected, 41 (77%) could be confirmed bioanalytically. Nine of the 11 substances tested for were detected, the exceptions being ibogaine and yohimbine. Psilocin, originating from ingestion of hallucinogenic mushrooms, was the most frequent drug accounting for 54% of the cases. The most common means of drug acquisition (56%) was purchase over the Internet. The patients using psychoactive plant materials were mainly young and commonly used the Internet for drug acquisition. Having access to bioanalytical methods for detection of plant-derived psychoactives is therefore considered important, when providing clinical toxicology service.
Research Interests: Adolescent, Humans, Female, Clinical, Poisoning, and 12 moreMale, Clinical Toxicology, Young Adult, Tandem Mass Spectrometry, Hallucinogens, High Pressure Liquid Chromatography, Middle Aged, Liquid Chromatography / Electrospray Ionization Mass Spectrometry, Plant extracts, Adult, Psychotropic Drugs, and Clinical evaluation
Intravenous methotrexate (MTX) therapy is widely used for treatment of various neoplastic diseases in children. The optimization of the MTX dose and/or the subsequent leucovorin rescue is based on pharmacokinetic data calculated from... more
Intravenous methotrexate (MTX) therapy is widely used for treatment of various neoplastic diseases in children. The optimization of the MTX dose and/or the subsequent leucovorin rescue is based on pharmacokinetic data calculated from plasma concentrations collected after cessation of the MTX administration. The influence of the MTX assay method on the subsequent pharmacokinetic evaluation was studied in 13 children with acute lymphoblastic leukemia. Plasma samples were collected after administration of MTX (5-8 g/m2) as 24 h infusions. All samples were analyzed by five different analytical procedures, viz. liquid chromatography (LC), enzyme inhibition assay (EIA), two fluorescence polarization immunoassays (FPIA1 and FPIA2) and enzyme multiplied immunoassay (EMIT). Using measurements from the four non-chromatographic procedures, only about 50% of determined pharmacokinetic parameters (area under the plasma concentration time curve, calculated by the trapezoidal rule and from pharmacokinetic modelling, and the terminal half life time) were within the range 75-125% of the values obtained from LC data. We conclude that the clinical outcome of MTX therapy using estimated MTX pharmacokinetics as guidelines for proper dosing of MTX and/or leucovorin rescue might be affected by the lack of accuracy of non-chromatographic procedures for MTX analysis. There is still a need for improving the accuracy of the procedures aimed at therapeutic drug monitoring of MTX.
Research Interests:
To evaluate the effects of a single dose of chloroquine (CQ) on the pharmacokinetics of methotrexate (MTX) in patients with rheumatoid arthritis. Eleven patients (ages 41-75 years) who were taking oral doses of MTX (15 mg/week) were... more
To evaluate the effects of a single dose of chloroquine (CQ) on the pharmacokinetics of methotrexate (MTX) in patients with rheumatoid arthritis. Eleven patients (ages 41-75 years) who were taking oral doses of MTX (15 mg/week) were studied after a dose of MTX alone and after a dose of MTX plus CQ (250 mg). Plasma and urine samples were collected for 24 hours after dose intake, and the concentrations of MTX and its major metabolite 7-hydroxymethotrexate were determined by high-performance liquid chromatography. Administration of CQ together with MTX caused a reduction in the area under the plasma MTX concentration versus time curve (AUC). The median value of individual AUC ratios (MTX/MTX + CQ) was 1.6 (95% confidence interval 1.2-3.6). The most likely mechanism for the interaction is that CQ reduces the bioavailability of MTX. This gives a possible explanation for a suggested reduction in MTX-associated liver toxicity by coadministration of CQ. The significance of the interaction for the therapeutic effect remains to be elucidated.
Research Interests:
Currently there is no approved pharmacotherapy for amphetamine dependence. Recent human laboratory studies have demonstrated that naltrexone modulates some of the reinforcing effects of amphetamine. The aim of this study was to... more
Currently there is no approved pharmacotherapy for amphetamine dependence. Recent human laboratory studies have demonstrated that naltrexone modulates some of the reinforcing effects of amphetamine. The aim of this study was to investigate the efficacy of naltrexone in comparison with placebo in reducing relapse to amphetamine use in amphetamine-dependent patients. Eighty patients who met DSM-IV criteria for amphetamine dependence were randomized to 12 weeks of double-blind naltrexone (50 mg) or placebo treatment. Patients visited the clinic twice weekly to receive medication and relapse prevention therapy and leave urine samples, which were analyzed for drug toxicology and for assessing adherence to medication via detection of naltrexone's metabolite (6-beta-naltrexol). The main outcome measure was abstinence from amphetamine use, as indicated by the total number of negative amphetamine urine samples during 12 weeks of treatment. All missing urine samples were defined for the analysis as positive for amphetamine. Overall, 55 patients (68.8%) completed the trial. The intention-to-treat analysis showed that the naltrexone group had a significantly higher number of amphetamine-negative urine samples compared with the placebo group. Survival analyses showed that the treatment groups differed in rate of continuous abstinence, in both the intention-to-treat and completer samples, in favor of naltrexone treatment. There was a significant reduction in craving levels and self-reported consumption of amphetamine in the naltrexone group compared with the placebo group. Treatment with naltrexone was well tolerated in this sample. This trial demonstrated the efficacy of naltrexone in reducing amphetamine use in amphetamine-dependent individuals.
Research Interests:
Research Interests:
Research Interests:
To compare two levels of psychosocial intervention in combination with acamprosate medication for the treatment of alcohol dependence. Patients (n = 70) were prescribed acamprosate and randomized to Minimal Psychosocial Intervention (MPI)... more
To compare two levels of psychosocial intervention in combination with acamprosate medication for the treatment of alcohol dependence. Patients (n = 70) were prescribed acamprosate and randomized to Minimal Psychosocial Intervention (MPI) or Extended Psychosocial Intervention (EPI). MPI patients met a psychiatrist for 20-30 min sessions on four occasions during a 6 month period. EPI patients were offered 10-15 sessions with a psychiatric nurse in addition to the visits to the psychiatrist. EPI patients were trained to use behavioural and cognitive coping skills to deal with high-risk situations in line with a manual developed for relapse prevention. Patients were assessed four times during the 24-week study by self-report and laboratory tests. Patients on average reported a decline in days with heavy drinking and in cumulative number of drinking days. No significant differences between patients in MPI and EPI were found with respect to heavy drinking, cumulative number of drinking days, number of days to first drink, or biomarkers of alcohol consumption. Higher age and lower level of education were significant predictors of treatment success. Adding more intensive individual treatments appears to add no extra improvement beyond that obtained by prescribing acamprosate and offering an infrequent consultation with a physician.
Research Interests:
This study compared two new methods for direct determination of 5-hydroxytryptophol glucuronide (GTOL) in urine, a biomarker for detection of recent alcohol consumption. Urine samples were collected from ten alcoholic patients during... more
This study compared two new methods for direct determination of 5-hydroxytryptophol glucuronide (GTOL) in urine, a biomarker for detection of recent alcohol consumption. Urine samples were collected from ten alcoholic patients during recovery from intoxication. A direct injection ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for measurement of the urinary GTOL to 5-hydroxyindoleacetic acid (5-HIAA) ratio, and an ELISA assay for direct measurement of GTOL, were used. Comparison was made with the urinary ethanol and ethyl glucuronide (EtG) concentrations. The breath ethanol concentration on admission ranged between 1.0-3.1 g/l. The UPLC-MS/MS method showed a median detection time of 39 h for an elevated urinary GTOL/5-HIAA ratio, while EtG was detected for a median of 65 h. Determination of GTOL by the ELISA assay showed 87% sensitivity in detecting positive samples at a 44% specificity, as compared with the UPLC-MS/MS method. The lower sensitivity of the urinary GTOL/5-HIAA ratio compared with EtG for recent drinking may be clinically useful, in cases where the EtG test provides an unwanted high sensitivity for intake of only small amounts of alcohol or unintentional ethanol exposure.
Research Interests: Psychology, Humans, Alcohol, Alcoholism, Alcohol Drinking, and 8 moreEthanol, Tandem Mass Spectrometry, High Pressure Liquid Chromatography, Liquid Chromatography / Electrospray Ionization Mass Spectrometry, Public health systems and services research, Biological markers, Neurosciences, and Enzyme Linked Immunosorbent Assay
Ethyl glucuronide (EtG) and ethyl sulfate (EtS) are conjugated ethanol metabolites formed in low amounts after alcohol consumption. Compared with ethanol, EtG and EtS are excreted in urine for a prolonged time, making them useful as... more
Ethyl glucuronide (EtG) and ethyl sulfate (EtS) are conjugated ethanol metabolites formed in low amounts after alcohol consumption. Compared with ethanol, EtG and EtS are excreted in urine for a prolonged time, making them useful as sensitive alcohol biomarkers. This study determined the detection times for EtG and EtS in alcoholic patients undergoing alcohol detoxification. Alcohol-dependent patients (n = 32) with an initial alcohol concentration >or=1 g/L based on breath testing were followed during detoxification. Urine samples for determination of EtG, EtS, ethanol and creatinine were collected on admission to the hospital and thereafter once daily for several days. EtG and EtS measurements were performed by liquid chromatography-mass spectrometry (LC-MS) and EtG also using an immunochemical assay (DRI-EtG EIA, ThermoFisher/Microgenics). The detection time for urinary EtG was weakly correlated (r = 0.434, P = 0.013) with the initial alcohol concentration (range 1.0-3.4 g/L). For EtG, the individual time range until return to below the applied cut-off limit (<0.5 mg/L) was approximately 40-130 h (median 78) with a similar time course observed for EtS. After correction for urine dilution, the time until an EtG/creatinine ratio <0.5 mg/g was approximately 40- 90 h (median 65). The detection times after an estimated zero ethanol concentration were approximately 30-110 h (median 66) for EtG and approximately 30- 70 h (median 56) for EtG/creatinine. The EtG results by LC-MS and the immunoassay were in good agreement. During alcohol detoxification, EtG and EtS remained detectable in urine for several days. The detection times showed wide inter-individual variations, also after adjusting values for urine dilution and to the estimated times for a completed ethanol elimination.
Research Interests: Psychology, Mass Spectrometry, Humans, Alcoholism, Female, and 16 moreMale, Ethanol, Detoxification, Individual variation, Alcohol Consumption, High Pressure Liquid Chromatography, Aged, Middle Aged, Alcohol dependence, Liquid Chromatography / Electrospray Ionization Mass Spectrometry, Adult, Public health systems and services research, Temperance, Neurosciences, Time Course, and Creatinine
To detect risk factors for sudden death from heroin injection. Evaluation of data from forensic investigations of all fatal cases of suspected heroin death in a metropolitan area. Only cases with detectable morphine and... more
To detect risk factors for sudden death from heroin injection. Evaluation of data from forensic investigations of all fatal cases of suspected heroin death in a metropolitan area. Only cases with detectable morphine and 6-monoacetylmorphine (6-MAM) in blood were included in order to select heroin intoxication cases. Stockholm, Sweden. Autopsy investigation and toxicological analysis of blood and urine; and police reports. In two-thirds of the 192 cases, death occurred in public places, and mostly without any time delay. Blood concentrations of morphine ranged from 50 to 1200 ng/g, and of 6-MAM from 1 to 80 ng/g. Codeine was detected in 96% of the subjects. In the majority of cases the forensic investigation indicated polydrug use, the most common additional findings being alcohol and benzodiazepines. However, in one-quarter of the cases other drug combinations were found. Previous abstinence from heroin and use of alcohol were identified as risk factors. For 6-MAM there was also a correlation with the presence of THC and benzodiazepines. Despite a high frequency of heart abnormalities (e.g. myocarditis and focal myocardial fibrosis), these conditions did not correlate with morphine or 6-MAM blood concentrations. We confirm that alcohol intake and loss of tolerance are risk factors for death from heroin use, whereas no connection to heart pathology was observed. Further, prospective, studies should focus on other possible risk factors.